Various types of air filter cartridges are used in respirators for filtration and removal of particulates and/or gases and vapors from the air. Current filtration devices are permanently encased in a metal or plastic shell/frame. This insures that there is no leakage between the filter and frame. When the filter reaches its loading capacity, the entire cartridge is discarded, including the shell. In many applications, such as high asbestos environments, these cartridges must be replaced frequently. The waste involved has prompted a need for a lower cost alternative to throw-away respirator cartridges.
The filter elements in throw-away filter cartridges are permanently sealed to the frame during manufacturing, under rigidly controlled conditions. A cartridge with a replaceable filter, however, must be designed so that the user can manually assemble the cartridge to create a positive, safe and reliable air-tight seal. Such a cartridge must also allow for easy filter replacement, must not be bulky, and must be cost effective.
The present invention is concerned with a solution to these problems.